/*********************************************************************
 * Copyright (C) 2002 Andrew Khan
 * <p>
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 * <p>
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 * <p>
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 ***************************************************************************/

package jxl.biff.formula;

import jxl.Cell;
import jxl.WorkbookSettings;
import jxl.biff.WorkbookMethods;
import jxl.common.Assert;
import jxl.common.Logger;

import java.util.Stack;

/**
 * Parses the excel ptgs into a parse tree
 */
class TokenFormulaParser implements Parser {
    /**
     * The logger
     */
    private static Logger logger = Logger.getLogger(TokenFormulaParser.class);

    /**
     * The Excel ptgs
     */
    private byte[] tokenData;

    /**
     * The cell containing the formula.  This is used in order to determine
     * relative cell values
     */
    private Cell relativeTo;

    /**
     * The current position within the array
     */
    private int pos;

    /**
     * The parse tree
     */
    private ParseItem root;

    /**
     * The hash table of items that have been parsed
     */
    private Stack tokenStack;

    /**
     * A reference to the workbook which holds the external sheet
     * information
     */
    private ExternalSheet workbook;

    /**
     * A reference to the name table
     */
    private WorkbookMethods nameTable;

    /**
     * The workbook settings
     */
    private WorkbookSettings settings;

    /**
     * The parse context
     */
    private ParseContext parseContext;

    /**
     * Constructor
     */
    public TokenFormulaParser(byte[] data,
                              Cell c,
                              ExternalSheet es,
                              WorkbookMethods nt,
                              WorkbookSettings ws,
                              ParseContext pc) {
        tokenData = data;
        pos = 0;
        relativeTo = c;
        workbook = es;
        nameTable = nt;
        tokenStack = new Stack();
        settings = ws;
        parseContext = pc;

        Assert.verify(nameTable != null);
    }

    /**
     * Parses the sublist of tokens.  In most cases this will equate to
     * the full list
     *
     * @exception FormulaException
     */
    public void parse() throws FormulaException {
        parseSubExpression(tokenData.length);

        // Finally, there should be one thing left on the stack.  Get that
        // and add it to the root node
        root = (ParseItem) tokenStack.pop();

        Assert.verify(tokenStack.empty());

    }

    /**
     * Parses the sublist of tokens.  In most cases this will equate to
     * the full list
     *
     * @param len the length of the subexpression to parse
     * @exception FormulaException
     */
    private void parseSubExpression(int len) throws FormulaException {
        int tokenVal = 0;
        Token t = null;

        // Indicates that we are parsing the incredibly complicated and
        // hacky if construct that MS saw fit to include, the gits
        Stack ifStack = new Stack();

        // The end position of the sub-expression
        int endpos = pos + len;

        while (pos < endpos) {
            tokenVal = tokenData[pos];
            pos++;

            t = Token.getToken(tokenVal);

            if (t == Token.UNKNOWN) {
                throw new FormulaException
                        (FormulaException.UNRECOGNIZED_TOKEN, tokenVal);
            }

            Assert.verify(t != Token.UNKNOWN);

            // Operands
            if (t == Token.REF) {
                CellReference cr = new CellReference(relativeTo);
                pos += cr.read(tokenData, pos);
                tokenStack.push(cr);
            } else if (t == Token.REFERR) {
                CellReferenceError cr = new CellReferenceError();
                pos += cr.read(tokenData, pos);
                tokenStack.push(cr);
            } else if (t == Token.ERR) {
                ErrorConstant ec = new ErrorConstant();
                pos += ec.read(tokenData, pos);
                tokenStack.push(ec);
            } else if (t == Token.REFV) {
                SharedFormulaCellReference cr =
                        new SharedFormulaCellReference(relativeTo);
                pos += cr.read(tokenData, pos);
                tokenStack.push(cr);
            } else if (t == Token.REF3D) {
                CellReference3d cr = new CellReference3d(relativeTo, workbook);
                pos += cr.read(tokenData, pos);
                tokenStack.push(cr);
            } else if (t == Token.AREA) {
                Area a = new Area();
                pos += a.read(tokenData, pos);
                tokenStack.push(a);
            } else if (t == Token.AREAV) {
                SharedFormulaArea a = new SharedFormulaArea(relativeTo);
                pos += a.read(tokenData, pos);
                tokenStack.push(a);
            } else if (t == Token.AREA3D) {
                Area3d a = new Area3d(workbook);
                pos += a.read(tokenData, pos);
                tokenStack.push(a);
            } else if (t == Token.NAME) {
                Name n = new Name();
                pos += n.read(tokenData, pos);
                n.setParseContext(parseContext);
                tokenStack.push(n);
            } else if (t == Token.NAMED_RANGE) {
                NameRange nr = new NameRange(nameTable);
                pos += nr.read(tokenData, pos);
                nr.setParseContext(parseContext);
                tokenStack.push(nr);
            } else if (t == Token.INTEGER) {
                IntegerValue i = new IntegerValue();
                pos += i.read(tokenData, pos);
                tokenStack.push(i);
            } else if (t == Token.DOUBLE) {
                DoubleValue d = new DoubleValue();
                pos += d.read(tokenData, pos);
                tokenStack.push(d);
            } else if (t == Token.BOOL) {
                BooleanValue bv = new BooleanValue();
                pos += bv.read(tokenData, pos);
                tokenStack.push(bv);
            } else if (t == Token.STRING) {
                StringValue sv = new StringValue(settings);
                pos += sv.read(tokenData, pos);
                tokenStack.push(sv);
            } else if (t == Token.MISSING_ARG) {
                MissingArg ma = new MissingArg();
                pos += ma.read(tokenData, pos);
                tokenStack.push(ma);
            }

            // Unary Operators
            else if (t == Token.UNARY_PLUS) {
                UnaryPlus up = new UnaryPlus();
                pos += up.read(tokenData, pos);
                addOperator(up);
            } else if (t == Token.UNARY_MINUS) {
                UnaryMinus um = new UnaryMinus();
                pos += um.read(tokenData, pos);
                addOperator(um);
            } else if (t == Token.PERCENT) {
                Percent p = new Percent();
                pos += p.read(tokenData, pos);
                addOperator(p);
            }

            // Binary Operators
            else if (t == Token.SUBTRACT) {
                Subtract s = new Subtract();
                pos += s.read(tokenData, pos);
                addOperator(s);
            } else if (t == Token.ADD) {
                Add s = new Add();
                pos += s.read(tokenData, pos);
                addOperator(s);
            } else if (t == Token.MULTIPLY) {
                Multiply s = new Multiply();
                pos += s.read(tokenData, pos);
                addOperator(s);
            } else if (t == Token.DIVIDE) {
                Divide s = new Divide();
                pos += s.read(tokenData, pos);
                addOperator(s);
            } else if (t == Token.CONCAT) {
                Concatenate c = new Concatenate();
                pos += c.read(tokenData, pos);
                addOperator(c);
            } else if (t == Token.POWER) {
                Power p = new Power();
                pos += p.read(tokenData, pos);
                addOperator(p);
            } else if (t == Token.LESS_THAN) {
                LessThan lt = new LessThan();
                pos += lt.read(tokenData, pos);
                addOperator(lt);
            } else if (t == Token.LESS_EQUAL) {
                LessEqual lte = new LessEqual();
                pos += lte.read(tokenData, pos);
                addOperator(lte);
            } else if (t == Token.GREATER_THAN) {
                GreaterThan gt = new GreaterThan();
                pos += gt.read(tokenData, pos);
                addOperator(gt);
            } else if (t == Token.GREATER_EQUAL) {
                GreaterEqual gte = new GreaterEqual();
                pos += gte.read(tokenData, pos);
                addOperator(gte);
            } else if (t == Token.NOT_EQUAL) {
                NotEqual ne = new NotEqual();
                pos += ne.read(tokenData, pos);
                addOperator(ne);
            } else if (t == Token.EQUAL) {
                Equal e = new Equal();
                pos += e.read(tokenData, pos);
                addOperator(e);
            } else if (t == Token.PARENTHESIS) {
                Parenthesis p = new Parenthesis();
                pos += p.read(tokenData, pos);
                addOperator(p);
            }

            // Functions
            else if (t == Token.ATTRIBUTE) {
                Attribute a = new Attribute(settings);
                pos += a.read(tokenData, pos);

                if (a.isSum()) {
                    addOperator(a);
                } else if (a.isIf()) {
                    // Add it to a special stack for ifs
                    ifStack.push(a);
                }
            } else if (t == Token.FUNCTION) {
                BuiltInFunction bif = new BuiltInFunction(settings);
                pos += bif.read(tokenData, pos);

                addOperator(bif);
            } else if (t == Token.FUNCTIONVARARG) {
                VariableArgFunction vaf = new VariableArgFunction(settings);
                pos += vaf.read(tokenData, pos);

                if (vaf.getFunction() != Function.ATTRIBUTE) {
                    addOperator(vaf);
                } else {
                    // This is part of an IF function.  Get the operands, but then
                    // add it to the top of the if stack
                    vaf.getOperands(tokenStack);

                    Attribute ifattr = null;
                    if (ifStack.empty()) {
                        ifattr = new Attribute(settings);
                    } else {
                        ifattr = (Attribute) ifStack.pop();
                    }

                    ifattr.setIfConditions(vaf);
                    tokenStack.push(ifattr);
                }
            }

            // Other things
            else if (t == Token.MEM_FUNC) {
                MemFunc memFunc = new MemFunc();
                handleMemoryFunction(memFunc);
            } else if (t == Token.MEM_AREA) {
                MemArea memArea = new MemArea();
                handleMemoryFunction(memArea);
            }
        }
    }

    /**
     * Handles a memory function
     */
    private void handleMemoryFunction(SubExpression subxp)
            throws FormulaException {
        pos += subxp.read(tokenData, pos);

        // Create new tokenStack for the sub expression
        Stack oldStack = tokenStack;
        tokenStack = new Stack();

        parseSubExpression(subxp.getLength());

        ParseItem[] subexpr = new ParseItem[tokenStack.size()];
        int i = 0;
        while (!tokenStack.isEmpty()) {
            subexpr[i] = (ParseItem) tokenStack.pop();
            i++;
        }

        subxp.setSubExpression(subexpr);

        tokenStack = oldStack;
        tokenStack.push(subxp);
    }

    /**
     * Adds the specified operator to the parse tree, taking operands off
     * the stack as appropriate
     */
    private void addOperator(Operator o) {
        // Get the operands off the stack
        o.getOperands(tokenStack);

        // Add this operator onto the stack
        tokenStack.push(o);
    }

    /**
     * Gets the formula as a string
     */
    public String getFormula() {
        StringBuffer sb = new StringBuffer();
        root.getString(sb);
        return sb.toString();
    }

    /**
     * Adjusts all the relative cell references in this formula by the
     * amount specified.  Used when copying formulas
     *
     * @param colAdjust the amount to add on to each relative cell reference
     * @param rowAdjust the amount to add on to each relative row reference
     */
    public void adjustRelativeCellReferences(int colAdjust, int rowAdjust) {
        root.adjustRelativeCellReferences(colAdjust, rowAdjust);
    }

    /**
     * Gets the bytes for the formula. This takes into account any
     * token mapping necessary because of shared formulas
     *
     * @return the bytes in RPN
     */
    public byte[] getBytes() {
        return root.getBytes();
    }

    /**
     * Called when a column is inserted on the specified sheet.  Tells
     * the formula  parser to update all of its cell references beyond this
     * column
     *
     * @param sheetIndex the sheet on which the column was inserted
     * @param col the column number which was inserted
     * @param currentSheet TRUE if this formula is on the sheet in which the
     * column was inserted, FALSE otherwise
     */
    public void columnInserted(int sheetIndex, int col, boolean currentSheet) {
        root.columnInserted(sheetIndex, col, currentSheet);
    }

    /**
     * Called when a column is inserted on the specified sheet.  Tells
     * the formula  parser to update all of its cell references beyond this
     * column
     *
     * @param sheetIndex the sheet on which the column was removed
     * @param col the column number which was removed
     * @param currentSheet TRUE if this formula is on the sheet in which the
     * column was inserted, FALSE otherwise
     */
    public void columnRemoved(int sheetIndex, int col, boolean currentSheet) {
        root.columnRemoved(sheetIndex, col, currentSheet);
    }

    /**
     * Called when a column is inserted on the specified sheet.  Tells
     * the formula  parser to update all of its cell references beyond this
     * column
     *
     * @param sheetIndex the sheet on which the column was inserted
     * @param row the column number which was inserted
     * @param currentSheet TRUE if this formula is on the sheet in which the
     * column was inserted, FALSE otherwise
     */
    public void rowInserted(int sheetIndex, int row, boolean currentSheet) {
        root.rowInserted(sheetIndex, row, currentSheet);
    }

    /**
     * Called when a column is inserted on the specified sheet.  Tells
     * the formula  parser to update all of its cell references beyond this
     * column
     *
     * @param sheetIndex the sheet on which the column was removed
     * @param row the column number which was removed
     * @param currentSheet TRUE if this formula is on the sheet in which the
     * column was inserted, FALSE otherwise
     */
    public void rowRemoved(int sheetIndex, int row, boolean currentSheet) {
        root.rowRemoved(sheetIndex, row, currentSheet);
    }

    /**
     * If this formula was on an imported sheet, check that
     * cell references to another sheet are warned appropriately
     *
     * @return TRUE if the formula is valid import, FALSE otherwise
     */
    public boolean handleImportedCellReferences() {
        root.handleImportedCellReferences();
        return root.isValid();
    }
}
